Anatomy's Questions



February 15 2015

Brachial Plexus

Write a short note on the formation of brachial plexus and its bracnhes

  • Last Comment by Neuros
February 15 2015 #

The brachial plexus is a plexus of nerves, which is responsible for the nerve supply of the upper limb including a few muscles of the trunk. 

Location: the plexus lies in the posterior triangle of the neck and partly in the axilla. It is divisible into two parts; supraclavicular and infraclavicular parts

The Roots:  the roots are formed by the anterior primary rami of C5, C6, C7, C8 and T1. Some contributions are made by the C4 and T2 which then is termed as either prefixed or postfixed plexus.

The Trunks: the roots from C5 and C6 join to form upper trunk, C7 forms the middle trunk and C8 and T1 join to form the lower trunk.

Division of Trunks: each trunk divides into vental and dorsal divisions.

Cords: the vental divisions of the upper and middle trunks form the lateral cord. The vental division forms the medial cord and the dorals divisions of all three trunks forms the posterior cord.


[1] Branches from the roots; 

  • Serratus Anterior
  • Rhomboideus

[2] Branches of the trunks;

  • Suprascapular nerve
  • Nerve to Subclavicus

[3] Branches of the cords; 

  • Lateral cord: Lateral pectoral, Musculocutaneous, Lateral root of median
  • Medial cord: Medial pectoral, Medial cutaneous nerve of arm, Medial cutaneous nerve of forearm, Ulnar nerve, Medial root of median nerve
  • Posterior cord: Upper subscapular, Nerve to latissmus dorsi, Lower subscapular, Axillary nerve and Radial nerve

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